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Jim Hunt

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Re: The 2018 melting season
« Reply #1900 on: July 03, 2018, 02:04:14 PM »
At the risk of drifting off topic, here's a recording of this morning's proceedings of the Great British Parliament's Environmental Audit Committee investigation into "The Changing Arctic":

https://goo.gl/qTFgRR
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oren

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Re: The 2018 melting season
« Reply #1901 on: July 03, 2018, 02:27:47 PM »
Mackenzie bay yesterday jul2. Relatively clear skies over the open water and ice in the center of the image allow a look at the surface temperatures using VIIRS band15.
Light blue ~-2C
Yellow       ~12C

edit: red ~6C
The bright red area is especially impressive considering it was ice-covered until recently.
If you can produce another such animation for the Chukchi melting front it would be most helpful.

Pagophilus

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Re: The 2018 melting season
« Reply #1902 on: July 03, 2018, 02:55:50 PM »
850 kPa information would have resulted in a different response.  However, you are correct regarding the manner of my response ... I should have asked you what you meant by your commentary instead of drawing a conclusion.

Quote
So choosing this information and writing that "most of the energy is inbound at high velocity and humidity at high altitude" seems wildly incorrect to me.
It

Pagophilus OK chum. There are only four attachments allowed per post here. The winds were in the region of 100kmph and carrying 100% humidity from 850 hpa or about 1.5 km altitude right up to the stratosphere with the high humidity areas at 500 and 250 closest matches for the dense tpw stream.  I was in a hurry,  so did not have time to gif the whole humidity altitude range for your pleasure. If you looked for yourself you would have seen that at surface and 1000hpa the winds were cooler, much slower and less humid. Check for me please what percentage of the atmospheres weight is above say 1km? And please don't accuse me of being misleading until you have calculated its energy flux coming in at 3 times the speed of the low altitude winds.
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uniquorn

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Re: The 2018 melting season
« Reply #1903 on: July 03, 2018, 04:56:21 PM »
Mackenzie bay yesterday jul2. Relatively clear skies over the open water and ice in the center of the image allow a look at the surface temperatures using VIIRS band15.
edit: red ~6C
The bright red area is especially impressive considering it was ice-covered until recently.
If you can produce another such animation for the Chukchi melting front it would be most helpful.
I suppose the Mackenzie bay has had increasingly warmer fresh melt water and plenty of silt since the beginning of june. In addition to the odd bit of sunshine and the occasional warm breeze.
Chukchi has been a bit cloudy for viirs recently.

Neven

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Re: The 2018 melting season
« Reply #1904 on: July 03, 2018, 05:08:36 PM »
NCEP Reanalysis temperature data for June (since 1948):

Arctic: 6th
Atlantic: 46th or thereabouts
Siberian: 1st (more than 1° C higher than previour record)
Pacific: 12th
Canadian: 37th or thereabouts
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uniquorn

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Re: The 2018 melting season
« Reply #1905 on: July 03, 2018, 05:36:34 PM »
<snippage>
 ice has been rotating in to the Mackenzie delta area from the 'Beaufort Gyre' region, then moving west up the Alaskan coast, meaning that a time series of AMSR2 concentration is not looking at the 'same' ice (as Oren noted up-forum).
That shows up in the post above and a worldview time series illustrates this movement pretty well, (not as cloudy as I expected). Except that quite a lot of ice doesn't make it up the Alaskan coast. Mackenzie bay appears to have it's own little killing zone.

edit: worldview terra/modis true color jun1-jul2
« Last Edit: July 03, 2018, 08:17:55 PM by uniquorn »

Tor Bejnar

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Re: The 2018 melting season
« Reply #1906 on: July 03, 2018, 06:06:53 PM »
Neven,
Remind us:  is "Arctic" 80-90N or 65-90N?  In other words, is "Arctic" the average of the four quadrants or is it a subset (northern end of) the (combined) four quadrants?
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Pagophilus

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Re: The 2018 melting season
« Reply #1907 on: July 03, 2018, 06:09:11 PM »
Winds appear to dragging considerable amounts of smoke from the central Siberian fires towards the ESS today, July 3 (Worldview image below, July 2 image for comparison). 

These winds are on the easternmost edges of the cyclonic system currently centered on the border between the Kara and Laptev seas.  Nullschool predicts winds in this smoky area as generally trending towards the north-east to north over the next 2-5 days.   A particularly thick patch of smoke looks set to stretch out a bit in the winds, and arrive over the ice tomorrow or the next day (assuming rain does not flush it out before then). 

Is there some significant lowering of the albedo of ESS ice (and/or adjacent ice) ahead?
« Last Edit: July 03, 2018, 06:19:54 PM by Pagophilus »
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oren

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Re: The 2018 melting season
« Reply #1908 on: July 03, 2018, 07:10:48 PM »
Winds appear to dragging considerable amounts of smoke from the central Siberian fires towards the ESS today
...
Is there some significant lowering of the albedo of ESS ice (and/or adjacent ice) ahead?
I'm not even sure smoke has a positive contribution to melting. Does it block sunlight and lowers effective insolation? I have no clue but someone probably does. As to albedo - is the effect significant? In Greenland it is as the particles accumulate, but on sea ice I'm not so sure.
I know all this belongs on the stupid questions thread, but as the subject came up...

RikW

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Re: The 2018 melting season
« Reply #1909 on: July 03, 2018, 07:45:45 PM »
i'd say if it falls on the ice it has a bad effect, because there will be less reflection, but as long as it is in the air during summer I'd guess it has a positive effect, blocking sunlight

RoxTheGeologist

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Re: The 2018 melting season
« Reply #1910 on: July 03, 2018, 07:57:47 PM »
i'd say if it falls on the ice it has a bad effect, because there will be less reflection, but as long as it is in the air during summer I'd guess it has a positive effect, blocking sunlight

This is CARBS take on it.

https://www.arb.ca.gov/cc/shortlived/meetings/03142017/final_slcp_report.pdf

"Airborne particulate matter (PM) varies in its composition and plays a significant role in
human health and the climate system. Particulate matter is emitted from a variety of
natural processes and human activities, and tends to remain in the air for only a few
days to about a week, resulting in extreme spatial and temporal variability. Among
different types of particles, carbonaceous particles (those that contain organic and black
carbon) are particularly important because of their abundance in the atmosphere. With
respect to climate impact, black carbon is the principal absorber of visible solar radiation
in the atmosphere while organic carbon is often described as a light-reflecting
compound."

see page 41.

On the release of this report, California started a huge drive to reduce methane emissions from diary farming.



Neven

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Re: The 2018 melting season
« Reply #1911 on: July 03, 2018, 08:00:31 PM »
Neven,
Remind us:  is "Arctic" 80-90N or 65-90N?  In other words, is "Arctic" the average of the four quadrants or is it a subset (northern end of) the (combined) four quadrants?

The graph says 65-90N, and for once I didn't make a mistake, so yes, 'Arctic' is the average temperature in all four quadrants combined, in short: Above the Arctic circle (which is 66°, but the NCEP analysis thingy changes it to 65N).
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Pagophilus

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Re: The 2018 melting season
« Reply #1912 on: July 03, 2018, 08:29:21 PM »
I am not sure either!  There are a lot of articles out there, some speculative, many referring to anthropogenic soot.  A quick search yielded a scientific article, JL Thomas et al., where they tracked soot particles (I use the term loosely here) from Canadian wildfires to the Greenland ice sheet. A positive albedo effect (increased melting) is thought to result from the particles when they are on the ice, but a precipitation event has to take the soot particles out of the atmosphere and onto the ice.  So wind alone is not enough.  And as you and RikW speculate, the smoke might actually protect the ice.  Not only that, but these Siberian wildfires could be part of the general background to melting, unless they are increasing.
 
I could only obtain the article abstract, which is available at https://agupubs.onlinelibrary.wiley.com/journal/19448007.

Below are some brief quotes from the Washington Post article based on this publication, which seemed pretty solid to me.  I won't clog up this thread with the whole article... url is below.

"Scientists have for the first time tracked soot from Canadian wildfires all the way to the Greenland ice sheet, where they found that the dark, sunlight-absorbing particles landed on the ice and had the potential to significantly enhance its melting — pointing to a possible new driver of sea level rise.
“That’s the first time we’ve been able to connect that whole logic chain from, here’s a fire and here’s where it ended up on the ice sheet,” said Chris Polashenski, one of the study’s authors and a researcher with the U.S. Army Corps of Engineers’ Cold Regions Research and Engineering Laboratory.
The study found that a specific atmospheric event, a snowstorm in late July and early August of 2013, was the critical factor in delivering the soot to the surface of Greenland. Without that storm to bring them down from the atmosphere to the surface, the soot particles could have traveled over the ice sheet at a high altitude and never landed.
“A lot of the time, the wind blows from a fire to the ice sheet and the black carbon doesn’t actually end up on the ice sheet,” said Polashenski.
.......
“It’s finally a scientific manifestation of a lot of speculation that was happening on the web, and I’m glad that there is now this paper that can provide some substance,” said Marco Tedesco, a Greenland researcher at the Lamont-Doherty Earth Observatory at Columbia University who was not involved in the study  ...  “The effect of these fires could add to the overall contribution of black carbon,” ...  "and then of course in the future, if it becomes more frequent, then yes, it could start playing a major role.”


https://www.washingtonpost.com/news/energy-environment/wp/2017/06/26/wildfires-can-cause-glaciers-to-melt-from-over-a-thousand-miles-away-scientists-find/?utm_term=.0d1a600c213c


Winds appear to dragging considerable amounts of smoke from the central Siberian fires towards the ESS today
...
Is there some significant lowering of the albedo of ESS ice (and/or adjacent ice) ahead?
I'm not even sure smoke has a positive contribution to melting. Does it block sunlight and lowers effective insolation? I have no clue but someone probably does. As to albedo - is the effect significant? In Greenland it is as the particles accumulate, but on sea ice I'm not so sure.
I know all this belongs on the stupid questions thread, but as the subject came up...
« Last Edit: July 04, 2018, 01:21:17 PM by Pagophilus »
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Michael Hauber

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Re: The 2018 melting season
« Reply #1913 on: July 03, 2018, 11:01:54 PM »
NCEP Reanalysis temperature data for June (since 1948):

Arctic: 6th
Atlantic: 46th or thereabouts
Siberian: 1st (more than 1° C higher than previour record)
Pacific: 12th
Canadian: 37th or thereabouts

Interesting and a little surprising to me that it was also the warmest June since 2012.  Combined with the very warm winter there may be potential yet to challenge for a record. 
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Thawing Thunder

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Re: The 2018 melting season
« Reply #1914 on: July 03, 2018, 11:27:08 PM »
Interesting and a little surprising to me that it was also the warmest June since 2012.  Combined with the very warm winter there may be potential yet to challenge for a record.

We will see very soon. Or there is a steep July cliff or there isn't any record. Still all cards are in the game.
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Lord M Vader

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Re: The 2018 melting season
« Reply #1915 on: July 03, 2018, 11:47:51 PM »
Whatever the final outcome will be, I'm fairly sure that we'll see an early September minimum this year.

Thawing Thunder

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Re: The 2018 melting season
« Reply #1916 on: July 04, 2018, 12:08:18 AM »
Whatever the final outcome will be, I'm fairly sure that we'll see an early September minimum this year.
Why? Early summer minima are due to cloudy weather (while the sun still shines). If there are open skies, there won't be an early freeze onset. So what is convincing you of the contrary?
« Last Edit: July 04, 2018, 12:26:30 AM by Thawing Thunder »
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Re: The 2018 melting season
« Reply #1917 on: July 04, 2018, 12:54:33 AM »
Quote
various inaccurate statements about the Beaufort over the last weeks
The imagery below shows the overall movement of the ice from mid-Sept 2017 to 02 July 2018, with the Beaufort region extracted and compared to Ascat. Only a few percent of the 289 days show a Beaufort Gyre pattern, not nearly enough to sustain the concept. The last month is better described as chaotic from day to day rather than cyclonic (or anti-cyclonic).

The melt season is not about the air pressure, clouds or insolation per se but rather their coupling to the ocean-ice-atmosphere system. Ice movement captures certain aspects of that in a directly observable fashion.

On the 17x17 grids, swaths of darkness indicate localized larger displacements; magenta patches represent measurement uncertainty. Ice movement has been distributed quite heterogeneously both in space and time, with the central Arctic by far the least affected, indeed exhibiting movement consistently antagonistic to "TransPolar Drift" as it is usually depicted.
« Last Edit: July 04, 2018, 01:11:11 AM by A-Team »

Michael Hauber

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Re: The 2018 melting season
« Reply #1918 on: July 04, 2018, 05:08:15 AM »
Whatever the final outcome will be, I'm fairly sure that we'll see an early September minimum this year.
Why? Early summer minima are due to cloudy weather (while the sun still shines). If there are open skies, there won't be an early freeze onset. So what is convincing you of the contrary?

Not sure what Lord Vader's reasoning may be, but I think we might be biased towards an early minimum because the core ice has been somewhat cooler and the fringe ice much warmer.  So late in the season the easy to melt ice will be gone and whats left will be stronger.  Still my personal opinion is that the weather near minimum would be more important.
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aperson

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Re: The 2018 melting season
« Reply #1919 on: July 04, 2018, 06:59:26 AM »
Looks like we will find out the effects of smoke on ice through observation soon
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aperson

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Re: The 2018 melting season
« Reply #1920 on: July 04, 2018, 08:41:12 AM »
Attached are earth nullschool 850 hPa temperature and total precipitable water for July 6 @ 06z. Given retrieval time, these should be based on the July 4 00z run of GFS.
« Last Edit: July 04, 2018, 08:53:23 AM by aperson »
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Lord M Vader

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Re: The 2018 melting season
« Reply #1921 on: July 04, 2018, 08:49:31 AM »
Whatever the final outcome will be, I'm fairly sure that we'll see an early September minimum this year.
Why? Early summer minima are due to cloudy weather (while the sun still shines). If there are open skies, there won't be an early freeze onset. So what is convincing you of the contrary?

Not sure what Lord Vader's reasoning may be, but I think we might be biased towards an early minimum because the core ice has been somewhat cooler and the fringe ice much warmer.  So late in the season the easy to melt ice will be gone and whats left will be stronger.  Still my personal opinion is that the weather near minimum would be more important.

Your are entirely correct Michael when you say that the easy ice should be gone by September whereas the thicker ice will remain solid. :) Another factor is that if this weather pattern continues into September it's more likely that we'll see an early minimum.

Cid_Yama

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Re: The 2018 melting season
« Reply #1922 on: July 04, 2018, 12:23:34 PM »
https://wxclimonews.com/2018/07/02/extreme-heat-event-in-northern-siberia-and-the-coastal-arctic-ocean-this-week/

Figured I would just post the link, rather than try to transfer all the great stuff in this article.
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Pagophilus

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Re: The 2018 melting season
« Reply #1923 on: July 04, 2018, 01:47:13 PM »
Looks like we will find out the effects of smoke on ice through observation soon
I would very much like to think so, but I have come to realize that it may be difficult.  Given that this area of the ESS/Laptev coast is scheduled for very high temperatures at the same time as the smoke is present, then those two variables might be hard to separate.  In addition, there is a good deal of precipitable water in this area.  If rain results then that rain may also have a melting effect on the ice (and produce a change in albedo by itself). 
On the other hand, such precipitation might also deposit the soot particles on the ice, and we might be able to see a distinctly darker area afterwards.  It would have to be very distinctive.  I am guessing this is tough to see though, because researchers would have spotted these direct relationships already. 
If there is a much lower-than-expected melting in this area despite all the circumstances, then that would hint at a cooling effect resulting from an increase of albedo from the smoke.  But again, how does one separate the variables?
« Last Edit: July 04, 2018, 02:03:30 PM by Pagophilus »
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Pagophilus

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Re: The 2018 melting season
« Reply #1924 on: July 04, 2018, 02:01:26 PM »
Looks like we will find out the effects of smoke on ice through observation soon

BTW, it looks from Worldview as though the smoke is above the clouds in this area.  In which case soot will not reach the ice in this area.  But, visually from Worldview, while the smoke seems to raise albedo when it is over land, once it is over the ice and the clouds, it is looks darker than what is beneath it.  Sheesh.  It's complicated.
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FredBear

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Re: The 2018 melting season
« Reply #1925 on: July 04, 2018, 03:31:14 PM »
Sorry to repeat myself but smoke from a bonfire on a frosty winter/spring day saps the heat from direct sunlight - that will act to protect the ice. The reflected radiation (albedo increase) will be gone but energy absorbed may reappear near the ice (but not if the smoke is above clouds)?

jdallen

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Re: The 2018 melting season
« Reply #1926 on: July 05, 2018, 02:29:32 AM »
Particulates from fire however will not.
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Re: The 2018 melting season
« Reply #1927 on: July 05, 2018, 02:49:04 AM »
The effects of smoke and black carbon are complicated. Pago is correct. The most powerful effect is surface darkening when soot falls on snow and ice. However, airborne black carbon can also cause warming at the top of inversions and increase insolation when low clouds might be present.

Yes, I too have felt the cooling effects of smoke overhead, but it's not that simple. when seas, clouds and ice are present.

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Re: The 2018 melting season
« Reply #1928 on: July 05, 2018, 03:28:06 AM »
Also smoke is very short lived (hopefully), but soot that falls on the ice lasts until the ice melts. Also the CO2 released by the fires lives for much longer, but the local immediate effect is probably trivial.
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Re: The 2018 melting season
« Reply #1929 on: July 05, 2018, 06:13:13 AM »
Omg the ESS shows a huge surface change from just a half day of supertorch.

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Re: The 2018 melting season
« Reply #1930 on: July 05, 2018, 07:48:26 AM »
Yes, ESS looks quite impressively dark on Worldview today, also with smoke from Siberian fires...

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Re: The 2018 melting season
« Reply #1931 on: July 05, 2018, 09:09:31 AM »
June 30 - July 4.

uniquorn

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Re: The 2018 melting season
« Reply #1932 on: July 05, 2018, 09:50:03 AM »
It must still be warm under all that smoke. Worldview ESS jul4-5.
edit: and the wind changed
edit: added a brightness/contrast altered image (imagej 39,211)
« Last Edit: July 05, 2018, 10:17:16 AM by uniquorn »

uniquorn

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Re: The 2018 melting season
« Reply #1933 on: July 05, 2018, 10:32:26 AM »
Interesting that windy ecmwf wam has >2m waves in the Mackenzie bay today. Is there a site on the ground that can verify that?

Thawing Thunder

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Re: The 2018 melting season
« Reply #1934 on: July 05, 2018, 11:01:19 AM »
Also interesting that there still exist ice bridges in the ESS and in the Beaufort that are not affected by waves. That hints at quite solid structures there, doesn't it?
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uniquorn

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Re: The 2018 melting season
« Reply #1935 on: July 05, 2018, 12:06:16 PM »
Quite solid ice bridge on jun29 (the last relatively clear day).https://tinyurl.com/yabrcqvu
edit:Beaufort, should have added ;)
edit2:sarcasm alert
« Last Edit: July 05, 2018, 06:10:54 PM by uniquorn »

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Re: The 2018 melting season
« Reply #1936 on: July 05, 2018, 12:29:11 PM »
Also interesting that there still exist ice bridges in the ESS and in the Beaufort that are not affected by waves. That hints at quite solid structures there, doesn't it?
No. It represents fast moving malleable ice jamming into chokes while the currents beneath that they were riding on continue their merry way.
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Peter Ellis

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Re: The 2018 melting season
« Reply #1937 on: July 05, 2018, 03:48:42 PM »
Quite solid ice bridge on jun29 (the last relatively clear day).https://tinyurl.com/yabrcqvu
edit:Beaufort, should have added ;)
Ice bridges don't form in open ocean, what on Earth are you talking about?  An ice bridge forms between the banks of a strait or river, and prevents the ice flowing with the current. It has to be anchored to both sides of the channel (i.e. at both ends of the bridge) in order to provide the necessary force.  Nothing in the picture you posted remotely resembles that.

Juan C. García

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Re: The 2018 melting season
« Reply #1938 on: July 05, 2018, 04:15:13 PM »
Ice bridges don't form in open ocean, what on Earth are you talking about? 

According to Peter Wadhams book "A Farewell to Ice", page 3, ice pressure ridges are formed on the Arctic Ocean. They could reach down 50 meters.

Edit:
Maybe that 50 meters was on 1976 and I am not able to distinguish a pressure ridge from above.
« Last Edit: July 05, 2018, 04:25:09 PM by Juan C. García »
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

uniquorn

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Re: The 2018 melting season
« Reply #1939 on: July 05, 2018, 04:35:23 PM »
Sorry everyone, I'll avoid sarcasm in future.
Though I did learn about ice ridges.

Pagophilus

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Re: The 2018 melting season
« Reply #1940 on: July 05, 2018, 04:39:30 PM »
For newbies like myself this might be interesting -- it involves the shape of things to come.  My apologies to all the old hands on deck. 

The limit of the ice along the Atlantic coast is pretty much defined by bathymetry, which shows how important melting from beneath is.  The limit is approximately the 500m submarine contour (edge of the Kara/Laptev shelves).  The reason for this boundary is that warm but salty and dense Atlantic waters take the plunge at this point.  The 2012 NSIDC source below states that if this boundary is violated, then we'll know a serious sea-change has occurred.

This melting season, that boundary has not been violated by Atlantification (to my interpretation), but it is being pressed (edging ever northwards).  The ice is melting up to that boundary more quickly to date, as far as I can tell from the Bremen AMSR2 records, than in any previous year. 

Now to the point of all this.   The boundary is obvious in the Barents Sea.  I think the boundary is also now becoming evident on the edges of the northern Kara in the Worldview image below (contrast enhanced b/c of clouds).   What I think I see here is the compact continuous pack ice running from the left of FJL, diagonally up to the top left of picture off the coast of the Severnaya Zemlya islands.  The rest of the northern Kara Sea (all the ice to the right of that compact CAB ice) seems to consist of a loose rubble of floes.  So it looks as if the ice melt is continuing apace up to the region of the 500m submarine contour.  I am not claiming this is unusual, but it does seem to be happening earlier than usual even in what seems to be a fairly standard melt year for the past few years.  There may also be continuous open water earlier than usual between the Kara and the Laptev Seas.

NSIDC bathymetry source:   http://nsidc.org/arcticseaicenews/tag/bathymetry/ 
« Last Edit: July 05, 2018, 05:33:36 PM by Pagophilus »
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Thawing Thunder

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Re: The 2018 melting season
« Reply #1941 on: July 05, 2018, 04:40:49 PM »
No. It represents fast moving malleable ice jamming into chokes while the currents beneath that they were riding on continue their merry way.

Ice bridges don't form in open ocean, what on Earth are you talking about?

According to Peter Wadhams book "A Farewell to Ice", page 3, ice pressure ridges are formed on the Arctic Ocean.

I humbly retract from the word "bridge" and for the sake of this discussion replace it with "ridge". My point still stands: There seems to be ice thick or jammed enough to withstand waves.

Interestingly, that ice on the Bremen graph doesn't look very solid:
« Last Edit: July 05, 2018, 04:53:12 PM by Thawing Thunder »
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oren

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Re: The 2018 melting season
« Reply #1942 on: July 05, 2018, 05:20:23 PM »
Interesting that windy ecmwf wam has >2m waves in the Mackenzie bay today. Is there a site on the ground that can verify that?

Also interesting that there still exist ice bridgesregions in the ESS and in the Beaufort that are not affected by waves. That hints at quite solid structures there, doesn't it?

TT, bear in mind that perhaps the ECMWF assumes there are no waves where there is high ice concentration. I think the actual situation of waves in that area cannot be known properly for lack of enough sensors, and therefore drawing conclusions from Windy's nice graphic is fraught with risk.

Hyperion

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Re: The 2018 melting season
« Reply #1943 on: July 05, 2018, 05:36:23 PM »
Or that concentration could be the result of floes. Surfing from Mackenzie and Chukchi ends.  Wave patterns from floes surfing can often be seen for a considerable distance into the pack. More likely I think a result of the strong current flow out of the base of the CAA meeting the Pacific inflow combined with the eastward Atlantic drift. Maybe the Chukchi elbow in the myi stringer ATeam was pointing out earlier was an early indication of this current confluences advance.
Very doubtful its anything to do with deep pressure ridge systems. The ice is too mushy these days for them to form. There could be bergs calved from North CAA and Greenland in there. But doubtful there would be enough of them for any serious anchoring of the pack on the shelf.
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Csnavywx

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Re: The 2018 melting season
« Reply #1944 on: July 05, 2018, 06:07:03 PM »
Given the trend and forecast, this year could contend with 2013's cool summer and end up over 5M on extent. I'm also thinking around 3.5M for area.

I don't see how we're going to break out of this pattern without significant changes in the North Atlantic SST pattern or a big Nino (or both). We may see this "stall" continue for a few years until deep ocean convection in the NATL corrects the large SST anomaly and helps flip the NAO/AO state back into negative territory. I suspect we'll see a relatively rapid drop in sea ice cover when that happens, but it could take 5-15 years (as it did in the 80s to early 90s).

The difference by that time will be the warming winter temps and significantly weakened spring volumes. 2016 was a small preview of that. I don't think much of the pack would survive a 2012 or 2007 style dipole with another 1C of winter warming.

Hyperion

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Re: The 2018 melting season
« Reply #1945 on: July 05, 2018, 06:36:46 PM »
Well past time for a voice from our last reporting ice tethered profiler. This little bot has been faithfully crawling 700m up and down it's rope under the ice, north of the CAA, tasting the Briney .
And it don't look good. Complete mixing to 700m depth is showing for the last three weeks, after a ragged few months in the last refuge of a stable halocline, the deep Canadian Arctic basin. 
This points to a near certainty of an unstoppable, even by the coming winter,  melt in the Arctic this year.
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FishOutofWater

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Re: The 2018 melting season
« Reply #1946 on: July 05, 2018, 06:47:42 PM »
The buoy figures are flashing over each other so it is impossible to examine the details of the curves. Please correct that problem. That is not how scientific data are presented - ever.

oren

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Re: The 2018 melting season
« Reply #1947 on: July 05, 2018, 06:50:32 PM »
I was just going to say, the delay in the animation is way too short for such complex graphs.

uniquorn

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Re: The 2018 melting season
« Reply #1948 on: July 05, 2018, 08:37:59 PM »
I appreciate the attempt to save space Hyperion but they are tricky to read as displayed.

Data is here http://www.whoi.edu/page.do?pid=160136

I see the change at ~day531 in salinity and dissolved oxygen as it approaches shallower water perhaps?

RoxTheGeologist

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Re: The 2018 melting season
« Reply #1949 on: July 05, 2018, 08:57:01 PM »

I don't understand these plots. There are two depth plots, 0-200 and 0-800(?) for each time increment, and they show different data. Which salinity is correct, for, say 25m at day 450?